Gen I Rx Hybrid Horsepower

[SOMEONE ELSE'S GOT MY NAME]

Just read a bit of Wikipedia's 400h description. Is my calculater bad? Check out the math regarding front electric motor, rear electric motor. When you add them together, their math would mean the ICE gets less than 100hp.

EDIT ... sorry for the spelling in the 'Topic' ... can't find how to edit, using the new board software (grumble grumble)

Powertrain

The gasoline-powered part of the RX 400h engine system is a 3.3 L 3MZ-FE V6, very similar to the one found in the RX 330. It produces 211 hp JIS (155 kW) and 288 N·m (212 ft·lbf).[9] The gasoline engine is aided by a maximum of two additional electric motors, one driving the front wheels, producing 167 hp JIS (123 kW) and 333 N·m (245 ft·lbf) and connected to the CVT gearbox,[9] and the other driving the rear wheels, producing 68 hp JIS (50 kW) and 130 N·m (95 ft·lbf).[9] The whole system, called Lexus Hybrid Drive (also Hybrid Synergy Drive), produces a maximum of 272 hp JIS (200 kW).[9] With Lexus Hybrid Drive, under normal driving conditions,

[cduluk]

Not one word of that makes sense to me...

If the gas engine produces 211hp, the first electric motor 167hp and second electric motor 88 hp... 211+167+68=446hp.

[lemon]

Lexus states the total HP for the 400h as 268. Not quite sure how they come up with this figure.

Maybe this explains it..

The engine makes a maximum of 208 horsepower at 5600 rpm, with 212 lb-ft of torque at 4400 rpm. The front motor makes 167 horsepower at 5600 rpm and 247 lb-ft of torque from zero to 1500 rpm - just the ticket for fast acceleration when needed. They are coupled through a planetary gear continuously-variable transmission, which is controlled by computers and motor-generator 1, which is also the starter motor. A second motor, with 68 hp from 4610 through 5120 rpm and 96 lb-ft of torque from zero to 610 rpm, runs the rear wheels when the control computer decides extra rear traction is needed. Around town, the RX operates electrically as much as possible, with the gas engine stopping when the car is stopped and assisting the electric motor(s) when moving. On the highway, the motors assist the engine. Note that the engine and motors never develop maximum power at the same time, but still, maximum system horsepower is listed at 268, not bad at all.

[cduluk]

How could the 400h be rated at 268hp? The 350 puts out 270, and it's SLOWER than the 400h

[lemon]

Torque, my friend. The torque from the electric motors is what pushes you back in your seat when you mash the go pedal. Look at how much torque the front electric motor is putting out - more than the gas engine, and it's available at zero rpm (i.e. immediately). I'm not making that number up - 268HP is from Lexus directly.

[RX400h]

The RX350's 0-60 time at best is 6.9 seconds while the RX400h's is 6.7 seconds. Having an electric "supercharger" definitely has its advantages. Couple the faster acceleration with better fuel mileage and you have a win-win vehicle. (Getting a $2000 tax break didn't hurt, either!)

[cduluk]

I wish they designed the Rx400h with an ECO/NORM/SPORT button like they've got on the newer hybrids.

With the gas engine and two electric motors all working together the Rx400h could haul some serious BUTT.

There are a lot of times in parking lots etc where I'd like the car to run electric only, and there are other times when I want some serious POWER.

If the engineers focused more on power than mpg they could make a REALLY powerful hybrid. The GS450h is a good example of this, but I know they can do even better...

[Gryphon]

Attached are the Lexus torque curves for all three propulsion sources.

I'm sure that the computer(s) determine the amount of HP and torque for various conditions.

Tom

RX400h front motor.pdf

RX400h ICE.pdf

RX400h rear motor.pdf

[cduluk]

Attached are the Lexus torque curves for all three propulsion sources.

I'm sure that the computer(s) determine the amount of HP and torque for various conditions.

Tom

I wonder if that can be tweaked?

:D

[Gryphon]

I wonder if that can be tweaked?

:D

You want a Dodge Viper killer RX400h?

Tom

[cduluk]

You want a Dodge Viper killer RX400h?

YES :whistles: I wouldn't mind more power from the 400h.

[DrDistorzion]

You want a Dodge Viper killer RX400h?

YES :whistles: I wouldn't mind more power from the 400h.

As you know I'm new to the RX, but I work with electric motors and my guess is that there are several reasons why the torque is limited.

First of all, the transmission must be dimensioned to cope with the torque, and if you add up all the torque from the 3 sources togeather you get over 700Nm, so if you where to develop a transmission to cope with that, it woul probably mean a pretty good elevation of an already high pricetag, and reliability and lifespan is priority for Lexus so I find it very natural that they prioritize lifespan and reliability instead of peak power.

But non the less I agree that I would also like different modes for the drivetrain, gaining more "manual" control over how it operates.

Maby a natural need for a technology nerd. :D